Three years after being rescued by private equity firm Thoma Bravo, security firm Blue Coat Systems has been sold on to another company in the same investment business, Bain Capital, for $2.4 billion (£1.59 billion) in cash.

The deal represents a near doubling of its money for Thoma Bravo, which took the firm private for $1.3 billion in February 2012 and that’s without factoring in any debt Blue Coat has acquired since then. On paper, this is a good deal.

Image: Blue Coat

Thoma Bravo was reportedly in recent negotiations to sell Blue Coat to defence firm Raytheon but this fell through and so Bain Capital’s interest is the desired exit.

The intention is to return Blue Coat to the stock market.

“We are very impressed with the profitable growth the company has demonstrated and believe strongly in the future growth of the cyber security market and Blue Coat’s position in this important sector,” said Bain Capital managing director, David Humphrey.

The sum paid and the fact that an IPO is even possible is a sign of the confidence the management have in Blue Coat and their belief that the security market remains buoyant.

After being taken over by Thoma Bravo, Blue Coat made acquisitions of its own, including Solera Networks in 2013 and anti-virus firm, Norman Shark, later the same year. Further back in time, Packeteer was bought in 2008.

It looks like being a successful turnaround for Blue Coat. Founded in 1996 as CacheFlow and once a company on the rise, by 2012 it was nearing the buffers with falling profits, sales going sideways and management coming and going.

The firm's first IPO was in November 1999 at the height of the dot.com craze.

In 2013 the firm also faced claims that its equipment was being used by Middle-Eastern governments with poor human rights records.